Shibata Fukashi, Hizume Masahiro
Biological Institute, Faculty of Science, Ehime University, Matsuyama 790-8577, Japan.
Chromosoma. 2002 Sep;111(3):184-91. doi: 10.1007/s00412-002-0197-1. Epub 2002 Jun 14.
In Allium wakegi, which is an allodiploid species between Allium cepa and Allium fistulosum, each genome can be clearly distinguished using genomic in situ hybridization (GISH). Genomic DNA of A. cepa and A. fistulosum is differentiated both qualitatively and quantitatively. We wanted to isolate nucleotide sequences that give genome-specific signals on A. cepa chromosomes in GISH experiments in A. wakegi. We isolated 23 clones that show GISH-like signal patterns in fluorescence in situ hybridization (FISH) and analyzed their distribution in the A. cepa- and A. fistulosum-derived genomes of A. wakegi. There was considerable variation in the abundance and distribution of these cloned sequences on the chromosomes of the two species. The degree of A. cepa specificity varied among the clones. Twenty-two of the clones showed an even distribution over most chromosome arms with some clustering in the pericentromeric regions, but one clone showed very distinct terminal signals on some chromosomes. Whereas these sequences are not specific for A. cepa, changes in bases in nucleotide sequences and in their amount result in genome-specific characteristics in GISH experiments.
在介于洋葱（Allium cepa）和葱（Allium fistulosum）之间的异源二倍体物种韭菜（Allium wakegi）中，使用基因组原位杂交（GISH）可以清楚地区分每个基因组。洋葱和葱的基因组DNA在质量和数量上都有差异。我们希望分离出在韭菜的GISH实验中能在洋葱染色体上产生基因组特异性信号的核苷酸序列。我们分离出了23个在荧光原位杂交（FISH）中显示出类似GISH信号模式的克隆，并分析了它们在韭菜的洋葱和葱衍生基因组中的分布。这些克隆序列在两个物种染色体上的丰度和分布存在相当大的差异。这些克隆对洋葱的特异性程度各不相同。22个克隆在大多数染色体臂上分布均匀，在着丝粒周围区域有一些聚集，但有一个克隆在一些染色体上显示出非常明显的末端信号。虽然这些序列并非洋葱所特有，但核苷酸序列中碱基的变化及其数量会在GISH实验中产生基因组特异性特征。
